Gilbert l



G. L. BAILEY.

Door Spring.

No. 17,070. Patented April 21. 1857.

GILBERT L. BAILEY, OF PORTLAND, MAINE.

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Specification of Letters Patent No. 17,070, dated April 21, 1857'.

To all whom it may concern:

Be it known that I, GILBERT L. BAILEY, of Portland, in the county of Cumberland, the State of Maine, have invented anew and useful Improvement on Door-Springs for Closing Doors; and I do hereby declare that the following is a full, clear, and exact description of the construction and opera tion of the same, reference being had to the annexed drawings, and to the letters of reference marked thereon, making a part of this specification, in which Figure 1 is a front elevated view of the spring as attached, and Fig. 2, a birds-eye view of a section showing the position of the lever when the door is partly open.

The nature of my invention consists in providing a volute, coniform spring, which is pressed upon by a lever when the door is.

opened, and its tendency to resume its original shape, closes the door by forcing the outer end of the lever, which has a roller attached, to the outer end of a guide fastened to the casing, and so formed as to cause the greatest pressure on the door when. it is nearly shut.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation.

My spring is made from thick sheet steel or other suitable metal, cut in lengths of about thirteen inches, and tapering in width from one half inch at one end to one quarter inch at the other, or thereabout. The strips are coiled into a volute coniform pile, the apex of the pile being formed of the narrow end of the steel strip. This spring is properly tempered, and placed on a thin plate of cast iron, or other metal, and is movable thereon, and from which projects a post A one and one half inches, with a slot in its outer end. This plate is screwed to the door T, near the top of the same, as shown in the accompanying drawings at 0. I do not however, intend to confine myself to the use of the bed-plate 0, in connection with the post, as the spring can be placed against the door; but it is preferable to have a hard substance for it to rest upon, consequently I employ the bed-plate; and to prevent the spring from working from under the lever L, I cast slight ledges, or flanges, on each edge of the plate.

In the slot of post A is fixed one end of lever L by a pin on which it plays: at the may be from ten to fifteen inches long. The

volute spring D, being placed on the plate 0 near post A, the lever is brought down upon its apex, and the roller at the other end is placed against guide X. When the door is opened the roller H follows guide X and passes in toward the hinge of the door, thereby compressing spring D; and the tendency of said spring to resume its conical form, causes it-to press against lever L, forcing roller I-I back to its original position, at the outer end of guide X, thereby closing the door: guide X is made slightly curving from its base toward the door, and just before reaching the outer end, the curve is made less, which gives an increased pressure on the door just as it is closing.

Some of the advantages of this door spring over most others in use, are, that it gives the greatest pressure on the. door when shut, and by the passage of the roller end of the lever in toward the hinge, the pressure is relieved or equalized, when the door is opened wide. It is durable, inasmuch as the spring has but little travel, and consequently is not liable to break readily. There is also a great advantage in applying this peculiar formed spring, which is sulficiently powerful, and occupies but a small space: and finally the whole is manufactured at a far less cost than any other good door spring.

The acting force of the spring D may be increased or diminished, by moving it farther from, or nearer to, the fulcrum of the lever, which is post A: this is an important advantage, and very convenient when applying it to doors of different sizes. I have also thought of various Ways in which a rubber spring could be applied, instead of the steel one, using the same lever, roller and guide, and accomplishing the same results.

I do not claim either of the within described parts separately in themselves, as

of my invention: neither do I claim in a X; the Whole arranged and operating, subdoor spring, making the pressure greatest stantially in the manner and for the purpose 10 when the door is closed: but set forth.

I do claim as my invention or improvement and desire to secure by Letters Pat- GILBERT BAILEY ent Witnesses The use ofthe volute coniform spring D, BENJ. KINGSBURY, J r., in connection With post A, lever L and guide JOHN SEAToN. 

